Unitary foam gravel roof covering

Abstract

A sprayed closed cell foam roof is prepared by applying the foam directly to the roof deck and layering the foam with sufficient gravel to prevent ultraviolet light deterioration of the foam. The roof is devoid of the waterproof layer conventional in foam roofs that leads to leaks and other failures common to such roofs.

I claim: 
     
       1. A roof structure comprising: a roof deck having an upper and a lower surface and having an air and water vapor permeable segment,   all segments of said deck supporting and being covered by an unbroken layer of sprayed closed cell foam material,   the vicinal lower surface of said foam layer being in direct contact with the upper surface of said permeable segment and   the upper surface of said foam layer being layered with gravel in an amount sufficient to prevent ultraviolet light deterioration of the foam.   
     
     
       2. The structure of claim 1 wherein the area of said permeable segment is less than the entire surface area of the said deck. 
     
     
       3. The structure of claim 1 wherein the area of said permeable segment is equal to the entire surface area of the said deck. 
     
     
       4. The roof structure according to claim 1 wherein the sprayed closed cell foam material is provided as layers of a depth of 2.5 cm or greater per layer. 
     
     
       5. The roof structure according to claim 1 wherein the sprayed closed cell foam material is layered to a depth of about 8-12 cm. 
     
     
       6. The roof structure according to claim 1 wherein the gravel layer is about 10-25 Kg/m 2 . of foam roof surface. 
     
     
       7. The roof structure according to claim 6 wherein the gravel layer is about 20 Kg/m 2 . of foam roof surface. 
     
     
       8. The roof structure according to claim 1 wherein the sprayed closed cell foam is of the polyurethane type. 
     
     
       9. A method of preparing a roof structure comprising the steps of: applying and affixing to all segments of the upper surface of a roof deck having an air and water vapor permeable segment, an unbroken layer of sprayed closed cell foam material,   the vicinal lower surface of said foam material being in direct contact with said permeable segment and   directly applying upon said foam layer, a layer of gravel sufficient to prevent ultraviolet light deterioration of the foam.   
     
     
       10. The method of claim 9 wherein the area of said permeable segment is less than the entire surface area of the said deck. 
     
     
       11. The method of claim 9 wherein the area of said permeable segment is equal to the entire surface area of the said deck. 
     
     
       12. The method according to claim 9 wherein the sprayed closed cell foam is applied in multiple layers to a total depth of about 8-12 cm. 
     
     
       13. The method according to claim 9 wherein the gravel layer is applied at a rate of about 10-25 Kg/m 2 . of foam roof surface. 
     
     
       14. The method according to claim 9 wherein the gravel layer is applied at a rate of about 20 Kg/m 2 . of foam roof surface. 
     
     
       15. The method according to claim 9 wherein the sprayed closed cell foam is of the polyurethane type.